The article in the Sydney Morning Herald states that they were only allowed back in (and were escorted) to get their stuff and get out. The 51 figure is saying

The article in the Sydney Morning Herald states that they were only allowed back in (and were escorted) to get their stuff and get out. The 51 figure is saying that the NSW Police believe that those units are structurally unsound, but the rest of the building is still evacuated all the same. I imagine GP misunderstood one of the article edits.